Research aimed at helping scientists calculate populations for commercial

Dana Hanselman, 25, is a fisheries biology doctoral candidate at the University of Alaska Fairbanks center at Auke Bay. He's one of four students nationwide to win a new type of federal grant in ocean sciences.

Hanselman will continue his researches, begun as a master's student at UAF, in how to apply adaptive sampling to rockfish populations. He's been part of a project begun several years ago by federal and university scientists.

The long-lived fish cluster in schools. That makes it hard for the usual random sampling to provide biologists with reliable population estimates. They need those estimates to know how many fish, which are mostly sold to the Japanese market, can be commercially harvested.

``If you're wrong, it's bad because they're so old,'' Hanselman said. ``If you overharvest them you can really knock them down for a long time.''

Under adaptive sampling, scientists change where they survey as they sample fish, in order to react to clusters. Instead of sampling at random, they take samples around schools of fish until they don't see that density anymore.

Why is that better? ``The first obvious reason is you're getting more samplings, and you're gauging more of the population,'' Hanselman said.

The technique seemed to work well for some species of rockfish in the Gulf of Alaska, said Jon Heifetz, a fishery research biologist at the National Marine Fisheries Service at Auke Bay.

``We ended up with more certain estimates of abundance, but we're not sure how to apply this in a larger survey area,'' said Heifetz, who is Hanselman's mentor for the fellowship.

The technique has been used in other fields, including forestry and studying clusters of diseases. But it's rarely been used for ocean fish populations, said Terry Quinn, professor of fish population dynamics at UAF.

The field work has included two sampling trips in a bottom trawler in the Gulf of Alaska. Hanselman proved his mettle the first week at sea as the ship tossed in 30 to 50 knot winds and he kept his meals down.

``I certainly wasn't thinking of this three years ago as an undergrad, since I was living on the Great Lakes,'' Hanselman said.

He was an engineering undergraduate student at the University of Michigan when he decided that wasn't the career he really wanted. He became interested in conservation during a semester in Belize and ended up with a degree in resource ecology.

Meanwhile, Professor Quinn was looking for an eager graduate student with good mathematical skills who could do the field work. ``I had a devil of the time finding someone who was going to be suitable for it.''

Hanselman's fellowship, of $32,000 in each of three years, is from the National Sea Grant College Program and the National Marine Fisheries Service. It will pay for his college tuition, and research and living expenses.

``The real exciting thing about that is it was a national competition,'' Quinn said. ``It says not only is he a good student but we're a pretty good program.''